Porous metallic scaffold substitutes for the replacement of damaged natural bone have been steadily gaining interest. Indeed, porous titanium and tantalum scaffold materials exhibiting good biocompatibility and bioactivity are currently commercially available. Nevertheless, from a mechanical perspective, these scaffolds are still considered inadequate for replicating the unique mechanical performance of natural bone, which is characterized by high strength, high specific strength, and low stiffness. This mechanical inadequacy is primarily attributed to the relatively low strength and high modulus of pure crystalline metals, which characteristics are inherited by the porous counterparts, resulting in poor replication of the load bearing capabilities of bone.
Another drawback of conventional porous metals is their inability to be processed into near-net-shapes, which is attributed to the poor superplasticity that characterizes conventional crystalline metals. Owing to this inability, the complexity of free-form fabrication of porous metallic scaffolds increases dramatically, resulting in substantially high manufacturing costs.